Boring-bar.



J. G. LUGENBILL.

BORING BAR.

APPLICATION FILED MAR. 4, 1911. 1,027,554. v Patented May 2s, 1912.

2 SHEETS-SHEET 1.

NTOR

J. G. LUGENBILL. BORING BAR.

APlLIGATION FILED MAR.4,.1911.

1,027,554. v Patented May 28, 1912.

2 SHEETS-SHEET 2.

as shall be more fully hereinafter described.; Referring to the drawings: Figure 1 is -aj TOI-IN Gr. LUGENBILL, OF PITCAIRN, PENNSYLVANIA.

BORING-BAR.

Specification of Letters Patent.

Patented May 28, 1912.

Application led March 4, 1911. Serial No. 612,431.

ble of very delicate and exact adjustment and comprising means for maintaining the Vcutters in operative engagement with the adjusting means, means for fixedly locating and securing the parts in position, and other features of improvement as. shall be more kfully hereinafter described.

Generally stated, the invention consists in yproviding with a main body portion or head` havinglaterally arranged cutters of blocks for adjusting the cutters, having inclined faces,

and an adjustable pin or stud provided with a coniform terminal interftting j between the faces of said blocks; a yoke member engaging said pin or stud;V an encircling sleeve having a threaded engagement with the boring bar and `an internal annular groove engaging the terminals of said yoke mem-ber, with means for mounting and adjusting said annular sleeve, and the-several other features and elements of the invention view in elevation of the operating portion ,ofa boring tool embodying my invention.

Fig. 2 is a vertical sectional viewthrough ythe middle portion ofl said bar, showing thev ladjusting stud and its connected parts elevation. Fig. 3 is al detail perspective view of one of the semicylindricalV halves of the adjusting sleeve. Fig. 4 is a similar view of the spring-pressed cutter shoe. Fig. 5 is a detail view in perspective of one of the springs fo'rsaid shoe. Fig. 6 is a central ver-y tical sectional view of the apparatus indicated by the line lVI. of Fig. 7, thefjcutters, yoke and avportion of the adjusting stl`id`being shown in elevation. Fig. 7 is a crosssection on the broken line VII. VII. of Fig. -6.k Fig. 8 is a detail perspective view of the ycovering ring for the adjusting sleeve. Fig.

.9'is a detail perspective view of one oftheI cutter adjusting blocks. Fig. 10 is a similar view of the adjusting stud and its yoke. Fig. 11 is a plan view in detail showing the adjusting. stud in section and in operative relation to the cutter adjusting blocks.

In the drawings, 2 represents the main body portion of the cutter bar or boring tool, or other equivalent mechanism, which'is generally cylindrical in form and constructed at its upper end or portion with a suitable terminal forinsertion'in the actuating head of the boring mill or machine, not shown. At or near its lower terminal, the bar 2 is provided with radially arranged cutters 3, 3, of any suitable construction, mounted in transverse sockets or openings 4V in the bar and abutting by their inner ends against the adjusting blocks 5, 5. Said blocks as shown, abut by their outer ends against the inner ends of the cutters 3 and are chamfered at their inner ends at a suitable angle to provide. sloping flat bearing faces 6, extending transversely across the inner faces of the blocks as shown. Each of said blocks is preferably provided with a longitudinal groove 7 into which projects the inner terminal of a set screw 8, providing for ample range of movement laterally, but limiting excessive travel ofthe blocks, whereby to prevent their removal or loss when the cutters 3 are removed.

Beneath the cutters 3 and blocks 5 in a i' downward extension of socket 4, transversely of the bar from one side to the other,

is located the cutter bearing shoe 9, preferably provided with a centering stud 10 entering a central aperture 11, said shoe bearing by its upper face against the under side of the cutters and blocks.

Located within dove-tail or other suitably shaped recesses 12 in shoe 9 arey springs 13 adapted to hold the shoe upwardly with suficient force against the cutters and blocks, to constantly forcek them into bearingV engagement with the top of transverse socket 4 and into constant operative engagement with theconiform terminal of the adjusting stud. Said adjusting stud 14 is cylindrical in form, mounted within ya centrally arranged cavity 15 of the bar 2, and having a y.coniform terminal 16 which bears by its annular face against the flat'sloping faces 6 of the adjusting blocks 5. The advantage of such construction is that as the adjusting stud is forced downwardly between the blocks,y itbears against them at opposite,

vall times.

Extending transversely through the upper portion of the .adjusting stud 14 is a yoke 17 lixedly secured therein by a set screw 18, said yoke being reinforced at its center by widening its middle portion asl shown and tapering outwardly toward each extremity-17, 17. The bar 2 is provided with a transverse clearance cavity 19 of sufficient depth to allow of the fullest extent of movement of the yoke, the width of the opening 19 corresponding to the width of the yoke 17.

The exterior of the bar 2 is threaded for a suficient distance and is embraced by a two-part adjusting sleeve a consisting of the semi-cylindrical halves 2O secured together by screws or bolts 21, said sleeve having interior threads 22 for engagement of the threads of the boring bar, and when joined and embracing the bar, constituting an adjusting nut. Said nut or sleeve is provided with an interior continuous annular groove 23 which embraces the terminals 17 of yoke 17 sufficiently accurately to prevent lost motion, whereby when the sleeve is adjusted by rotation upon its threads, the yoke and stud 111 will be correspondingly adjusted vertically. The sleeve sections are provided with upwardly extending terminals 24 engaging suit-able receiving cavities 25 surrounding the bar, and are covered by an encircling covering ring 26 secured to the bar by screws 27 or other suitable means, and projecting downwardly from the sleeve extensions. By this means all dirt or foreign matter is excluded from t-he interior, keeping the working portions in clean, serviceable condition for accurate operation.

The lower terminal 28 of sleeve a is tapered to provide an edge engagement with the outer surface of the bar 2, and it and the bar .are provided with micrometer gage divisions Z), c, whereby to accurately determine the adjustment of the cutters.

Wlhat I claim is 1. A boring tool comprising a rotatable head having transversely arranged cutters,

adjusting blocks therefor having sloping inner ends, a tapered spreader bearing thereagainst and having a transverse yoke, and a ring on said head, said ring having an inner circumferential groove engaging said yoke, substantially as set forth.

2. A boring tool comprising a rotatable head having transversely arranged cutters, adjusting blocks therefor having sloping inner ends, a tapered spreader bearing thereagainst, and means embodying a transverse yoke and a rotatable ring on said head, said ring Shaving an inner circumferential groove for adjusting the spreader, substantially as set forth.

3. The combination with a rotatable head having a transverse cut-ter socket, of cutters therein, adjusting blocks having inner flat tapered faces, a tapered spreader bearing thereon provided with a laterally extending yoke, and a two .part ring on said head, said ring having an inner circumferential groove, engaging the yoke, substantially as set forth.

4. rfhe combination with a rotatable head having a transverse cutter socket, of cutters therein, adjusting blocks having inner flat tapered faces and longitudinal slots, retaining pins projecting into said slots, a tapered spreader bearing on said adjusting blocks provided with a laterally extending yoke, and a ringon said head, said ring having an inner circumferential groove, engaging the yoke, substantially as set forth.

5. The combination with a rotatable head having a transverse cutter socket, of cutters therein, adjusting blocks having inner flat tapered faces, a tapered spreader bearing thereon, and means embodying a ring on said head, said ring having an inner circumferential groove, and a set screw for adjusting and fixedly securing the spreader, substantially as set forth.

6. The combination with a rotatable head having a transverse cutter socket, of cutters therein, adjusting blocks having inner flat tapered faces, a tapered spreader bearing thereon having a transverse yoke, and a ring threaded on said head, said ring having an inner yannular closed groove engaging the terminals ofthe yoke, substantially as set forth.

7. The combination with a rotatable head having a transverse cutter socket, of cutters therein, adjusting blocks having inner fiat ltapered faces, a vbearing shoe for the cutters having dovetail cavities and springs therein, and a tapered spreader engaging the adjusting blocks, substantially as set forth.

8. In a bar ofthe class described, a main cylindrical stem having transverse micrometer gage divisions, laterally adjustable cutters mounted vin the stein, means in the interior of the stem for adjusting the cutters, and a sleeve threaded on the stem engaging said adjusting means and provided with a beveled terminal having longitudinal micrometer gage ,divisions in operative relation `to the divisions on the stem, substantially as set forth.

9. The combination with a rotatable Ahead having a transverse cutter socket, of cutters therein, adjusting blocks having inner flat tapered faces, a tapered spreader having a transverse yoke, a sleeve threaded on the head having an annular groove engaging the terminals of the yoke, and a ring secured to the head and overlapping the end of the sleeve, substantially as set forth.

10. The combination with arotatable head having a transverse cutter socket, of cutters therein, adjusting blocks having inner fiat tapered faces, a tapered spreader vhaving a transverse yoke, a two-part longitudinally integral sleeve threaded on the head having an annular groove engaging the terminals of the yoke, and a ring secured to the head and overlapping the end of the sleeve, substantially as set forth.

11. A boring tool comprising a rotatable head having transversely arranged cutters adjacent its .entering end, adjusting blocks therefor having sloping inner ends, an adjusting stud having a tapered terminal bearing thereagainst and yextending longitudinally through the center of the rotatable head backWardly from its entering end, a

head backwardly from its entering end hav- Y ing a laterally extending yoke, and a longitudinally integral rotatable adjusting ring having an inner annular` groove engaging said yoke, substantially as set forth.

Intestimony Whereof I hereunto aiiX my signature in the presence of t-Wo Witnesses. J OHNG. LUGENBILL. A Witnesses:

C. M. CLARKE, CHAs S. LEPLEY.

Copies of this patent may be obtained for ve cents each, by addressing` the Commissioner of Patents,

Washington, D. C. 

